Best option to power my project

I have made a pretty standard Bluetooth smart outlet using a relay board. I have moved from the prototype with breadboard and Uno to directly connecting to an Arduino Nano. The issue for me is that I don’t want to use the computer a mini-USB to power it, so I know that I could simply hook up a 9-volt to the vcc (right?) but I am not sure where or how to ground it. The diagram is below and the Nano has just 2 GND pins. Any help would be appreciated.

Both ground pins are common to each other (no difference). Hook it which ever one is closest.

dfoliver:
The issue for me is that I don’t want to use the computer a mini-USB to power it, so I know that I could simply hook up a 9-volt to the vcc (right?)

I hope you don’t mean a 9volt PP3 battery.
The easiest way to power this is a common 5volt phone charger with mini USB plug.
Leo…

So can I use the Hdmi/ mini usb cord I got with the Nano and and phone plug I with Hdmi have lying around?

BTW, I meant Vin not Vcc.

dfoliver:
So can I use the Hdmi/ mini usb cord I got with the Nano and and phone plug I with Hdmi have lying around?

I never got an HDMI cord with any of my Nanos, nor did I get a phone plug. Are you pulling my leg now?

The best option to power your project (without you telling us more info), is with solar power.

I got a cord, but not the phone plug.

Do you have any solar panels?

I do, on my roof.

Then, why not use free electricity. May need some batteries if you want your project to run through the night. May be able to put it to sleep at night tho. What do you think?

I do hope you know how to charge a mobile phone.
I use a plug-in power supply with a USB socket.
Or one with permanently attached mini-USB plug.

That same 5volt charger can also be used to supply your Arduino.

HDMI is for digital video/audio and other data.
A phone lead is used to connect a telephone to the wall outlet of the telephone company.
Leo..

Thank you, I appreciate that. Not sure why keep talking about HDM, working too hard…